The present disclosure relates to a ceramic dielectric composition able to be used in automotive electronics and having excellent mechanical strength and electrostatic discharge (ESD) protection characteristics, and a multilayer ceramic capacitor containing the same.
In general, electronic components using a ceramic material, such as capacitors, inductors, piezoelectric elements, varistors, or thermistors, or the like, include a ceramic body formed of a ceramic material, internal electrodes formed in the ceramic body, and external electrodes mounted on surfaces of the ceramic body to be connected to the internal electrodes.
Among ceramic electronic components, multilayer ceramic capacitors commonly include a plurality of stacked dielectric layers, internal electrodes disposed to face each other with respective dielectric layers interposed therebetween, and external electrodes electrically connected to the internal electrodes.
Multilayer ceramic capacitors have been widely used as components of mobile communications devices such as tablet computers, personal digital assistants (PDA), mobile phones, and the like, due to inherent advantages thereof, such as a small size, high capacitance, ease in the mounting thereof, and the like.
Particularly, multilayer ceramic capacitors for automotive applications should have excellent mechanical strength and excellent electrostatic discharge (ESD) protection characteristics.
Generally, a dielectric material satisfying X7R characteristics as a ferroelectric material, or a C0G-based (C-zero-G) paraelectric material, have been used as a ceramic dielectric composition applied to a multilayer ceramic capacitor having electrostatic discharge (ESD) protection characteristics.
A ferroelectric material has a high degree of permittivity, and thus provides an advantage in that a dielectric layer may be designed to be relatively thick. However, when evaluating electrostatic discharge (ESD) protection characteristics, electrostrictive cracks may occur under a high electric field environment or capacitance may be decreased due to DC-bias characteristics, such that a higher voltage may be actually applied to the capacitor, thereby deteriorating the ESD protection characteristics.
The C0G-based paraelectric material has a low permittivity, such that a dielectric layer should be relatively thin, and thus, withstand voltage characteristics may be deteriorated, such that ESD protection characteristics may not be satisfied.
Therefore, research into a dielectric material having relatively high permittivity due to permittivity that remains unchanged regardless of a direct current (DC) electric field, while having excellent DC-bias characteristics, as a dielectric composition of an automotive electrostatic discharge (ESD) protection capacitor, has been required.